1. Technical Field
The present invention relates to blending plant fertilizer constituents and more particularly, the present invention relates to tailoring the ratio of nutrients in a fertilizer composition by colorizing fertilizer constituents according to their nutrient content and mixing the colorized fertilizers until the resultant color matches a reference color associated with a desired fertilizer composition.
2. State of the Art
Plants are harvested for a variety of useful products. Although some plants are coveted for their leaf such as spinach and lettuce, the stalk such as asparagus, and the root such as carrots, most plants are useful for some aspect of their reproductive cycle, such as the flowering portion (roses), the fruit such as avocado, and the seed such as corn and wheat. In addition to water and carbon dioxide that plants require to grow, plants also require minerals to grow in a healthy manner, and to provide us with those nutrients that are essential to our own health. These minerals are normally absorbed through the roots, though in some cases foliar application is effective. Although the specific needs and relative proportions of nutrients needed by different species of plants may vary, as a general rule, all plants require the same nutrients. The necessary proportions, however, vary from specie to specie, as well as throughout the life cycle of a plant. Environmental ranges of light, temperature, humidity, airflow, etc. can also have a controlling effect on ideal nutrient composition for various crops in their range.
“Primary nutrients” include nitrogen, phosphorus, and potassium, commonly referred by the triplet “NPK.” These are called primary because they are usually needed in the greatest proportion relative to other nutrients. “Secondary nutrients” include calcium, magnesium, and sulfur, usually in the form of sulfate. Trace element needs include iron, manganese, zinc, copper, boron, chloride, and molybdenum. Though the studies are in their formative stages, more recent evidence shows that cobalt, silicon, nickel and chloride are also needed, or helpful to plant growth, in trace amounts. The secondary nutrients are typically required in lesser quantities than the primary nutrients, but higher quantities than the trace elements. There is, however, some overlap. For example, calcium, listed above as a secondary nutrient, is often needed in higher quantities than phosphorus.
The required levels for some nutrients remain fairly stable over the life cycle of the plant. For other nutrients, however, the requirement levels vary significantly throughout the life cycle. Accordingly, the production of a healthy leaf at the beginning of a life cycle may have significantly different nutritional needs than the production of flower, fruit, or seed near the end of the life cycle.
Most plants are satisfied by a balance of nutrients at levels that remain fairly stable over the life of the plant. A few nutritional requirements, however, such as nitrogen, phosphate and magnesium often have a wide range of variation over the life of a plant for optimum growth, vigor, and yield. Young plants require high levels of nitrogen to enable their early structural growth of roots, stems, and foliage. At a later stage in a plants growth, such as the flowering, fruiting or seed production stages, the need for nitrogen decreases significantly. Simultaneously, the need for other nutrients may increase throughout the life of a plant. For example, phosphate and magnesium are important for flowering, and the required levels frequently increase during this stage of development. Because of this, it is not possible to maintain nutrients at optimal simply by increasing or decreasing the strength, or concentration, of a single general purpose fertilizer. The ratio between elements and their variation throughout the plant's lifecycle is a key to optimum growth and productivity.
As a consequence, gardeners, farmers, horticulturists and other plant growers collectively referred to herein as “growers,” will typically apply a variety of fertilizers throughout the life of a plant. Our method provides a simple building-block method for the grower to easily mix a huge range of precise fertilizer blends.
The first problem is the life cycle of a plant. It is not as if the plant shifts from one stage to another in digital fashion. The process is an analog one, where the need for one nutrient decreases gradually as the need for another gradually increases. The more frequently the formula is adjusted throughout a plant's life, the more closely the mixture can follow the optimal ratio. Additionally, there is the problem of plant types. Different types of plants have different needs throughout their life cycle. To optimally meet the nutritional needs of the multiple stages of a life cycle for hundreds of different types of plants, over a range of environmental variations like field and greenhouse, summer, and winter, requires many different fertilizer formulas. Because it is not practical to manufacture, purchase or store an exhaustive or even extensive range of different fertilizer formulations, growers commonly try to formulate optimal, or near optimal mixtures by mixing a handful of basic fertilizer products in different ratios throughout the life cycle of a plant. Typically the measuring and mixing is by weight percentages, or may be volumetric for less sophisticated growers. There are drawbacks of such mixtures, however. A first drawback is that an optimal mixture is seldom a simple integral ratio of small numbers, such as “three parts of a first fertilizer and two parts of a second fertilizer.” If an optimal ratio is closer to one hundred to one, and the grower does not need one hundred measures of fertilizer, the grower scales back the total amount of fertilizer and “eye-balls” the amounts used. The process immediately becomes an inexact science, forming a sub-optimal fertilizer. Another problem with volumetric measuring is that granulated solids, particularly fertilizers, can “clump” together, upsetting the measured volume required for an ideal ratio. Variations in the densities of fertilizers can occur through settling, impurities, and a variety of other causes. Moreover, in large commercial operations, fertilizers may not be placed in tidy graduated flasks before mixing. They can be dumped together from large bins or scoops lacking exact gradations, or being filled in very rough and inexact amounts. Air pockets can also form in a volume, affecting the actual amount of fertilizer used. Another problem with volumetric mixing is the language barrier. For example, in growing hydroponic tomatoes, the same fertilizer may be marketed in Mexico, Iran and China. Instructions for optimal fertilizer mixtures in Spanish will be of little value in Chinese or Farsi. In short, volumetric mixing of fertilizer formulas to obtain a particular formula for a particular stage of life of a particular plant can be inexact, tedious, boring, and difficult to communicate from language to language.
Coloring in the prior art includes U.S. Pat. No. 1,513,542 to Flagg. which is directed to using color coding to determine an amount of hemoglobin in the blood. U.S. Pat. No. 2,452,385 to Merckel relates to test apparatus for testing chemical presence and concentrations using colors. A translucent container has a colored translucent band around an upper portion of the container to serve as a color comparator against a solution within the container. Because the band is translucent, the light passing through the band serves as a concentration comparator as well. The apparatus can be used to test free chlorine in water, or can be used to test soils for mineral content such as nitrogen or potash. The soil sample is mixed in water with an indicator selected to react with the nitrogen or other mineral to produce a color. As the soil settles on the bottom, the color of the liquid can be compared to the colored band. Merckel teaches chemical alteration of a small test sample, not the entire target substance. Merckel selects a testing agent which produces certain shades and colors when it reacts with chemicals already in the sample substance. This testing agent may or may not produce a specific color, depending on the presence of underlying chemicals in the target substance. U.S. Pat. No. 4,126,417 to Edwards is directed to a testing and treatment kit for soil pH and nitrate levels. A stick with color coding allows the user to match a pH level or nitrate level to a color to determine concentrations. Pills can then be dissolved in water to adjust the pH or nitrate content of the soil. To distinguish nitrate enhancing pills from acid enhancing pills, nitrate enhancing pills are colored differently than acid enhancing pills. Modern commercial growers use ionic detection with computers to determine and maintain optimum nutrient character and strength at considerable cost and complexity. Examples of such complex system include the Priva™ Nutriflex™ and Priva™ Nutrifit™ systems from Priva B.V., The Netherlands; systems that may be used to control nutrients for state-of-the-art hydroponic greenhouses.